Total joint arthroplasty (TJA) is a relatively safe orthopedic procedure. However, complications do occur, and some may necessitate admission to the intensive care unit (ICU). Our purpose was to determine risk factors associated with admittance to ICU after TJA. We evaluated 22 343 primary and revision total hip and knee arthroplasties from 1999 to 2008. One hundred thirty patients were admitted to the ICU. Cases were matched 1:2 for date of surgery, surgeon, and type of surgery. The causes for admission to ICU were recorded. Independent risk factors for ICU admission were smoking, cemented arthroplasty, general anesthesia, allogenic transfusion, higher C-reactive protein, lower hemoglobin level, higher body mass index, and older age. Proper identification and management of these “at-risk” patients may decrease the incidence of ICU admittance after TJA.